Document
CAT3643
3-Channel Ultra High
Efficiency LED Driver
Description
The CAT3643 is a high efficiency fractional charge pump that can drive up to three LEDs programmable by a one wire digital interface. The inclusion of a 1.33x fractional charge pump mode increases device efficiency by up to 10% over traditional 1.5x charge pumps with no added external capacitors.
Low noise input ripple is achieved by operating at a constant switching frequency which allows the use of small external ceramic capacitors. The multi−fractional charge pump supports a wide range of input voltages from 2.4 V to 5.5 V.
The EN/DIM logic input functions as a chip enable and a digital dimming interface for current setting of all LEDs. Six different current ratios are available via the interface.
The device is available in the 16−pad TQFN or 12−pad TDFN 3 mm x 3 mm package with a max height of 0.8 mm.
ON Semiconductor’s 1.33x charge pump switching architecture is patented.
Features
• High Efficiency 1.33x Cha.